I haven't bothered with JPEGs out-of-camera for maybe a decade now (no time pressure to get my shots to someone). I don't use raw and JPEG together as the approach to exposure is different with raw.

With raw, you want as many photons as is possible without blowing anything (other than specular highlights) out. This is called "expose to the right", which you'll see in forums as "ETTR". Exposing this way with raw will give you at least another stop of dynamic range.

How to do this? Pretty simple: look at your RGB histograms; you want the tiniest possible gap between the shown data and the right-side border, or at least have the data not crawling up the right wall.

Digital noise comes from a lack of photons; if you can expose a bit longer or wider (i.e. ETTR) you'll get less noise in the darkest parts of your shot - and a lower 'noise floor' means more dynamic range.